Average
MCQs Math


Question:     Find the average of even numbers from 12 to 958


Correct Answer  485

Solution And Explanation

Solution

Method (1) to find the average of the even numbers from 12 to 958

Shortcut Trick to find the average of the given continuous even numbers

The even numbers from 12 to 958 are

12, 14, 16, . . . . 958

After observing the above list of the even numbers from 12 to 958 we find that the difference between two consecutive terms are equal. This means the list of the even numbers from 12 to 958 form an Arithmetic Series.

In the Arithmetic Series of the even numbers from 12 to 958

The First Term (a) = 12

The Common Difference (d) = 2

And the last term (ℓ) = 958

The average of the numbers forming an Arithmetic Series

= The first term (a) + The last term (ℓ)/2

⇒ The average of numbers forming an Arithmetic Series = a + ℓ/2

Thus, the average of the even numbers from 12 to 958

= 12 + 958/2

= 970/2 = 485

Thus, the average of the even numbers from 12 to 958 = 485 Answer

Method (2) to find the average of the even numbers from 12 to 958

Finding the average of given continuous even numbers after finding their sum

The even numbers from 12 to 958 are

12, 14, 16, . . . . 958

The even numbers from 12 to 958 form an Arithmetic Series in which

The First Term (a) = 12

The Common Difference (d) = 2

And the last term (ℓ) = 958

The Average of the given numbers

= Sum of the given numbers/Total number of given numbers

Thus, to find the average of the given numbers, first, we need to find their sum and the total number of given numbers

Finding the number of terms

For an Arithmetic Series, the nth term

an = a + (n – 1) d

Where

a = First term

d = Common difference

n = number of terms

an = nth term

Thus, for the given series of the even numbers from 12 to 958

958 = 12 + (n – 1) × 2

⇒ 958 = 12 + 2 n – 2

⇒ 958 = 12 – 2 + 2 n

⇒ 958 = 10 + 2 n

After transposing 10 to LHS

⇒ 958 – 10 = 2 n

⇒ 948 = 2 n

After rearranging the above expression

⇒ 2 n = 948

After transposing 2 to RHS

⇒ n = 948/2

⇒ n = 474

Thus, the number of terms of even numbers from 12 to 958 = 474

This means 958 is the 474th term.

Finding the sum of the given even numbers from 12 to 958

The sum of all terms (S) in an Arithmetic Series

= n/2 (a + ℓ)

Where, n = number of terms

a = First term

And, ℓ = Last term

Thus, the sum of all terms (S) of the given even numbers from 12 to 958

= 474/2 (12 + 958)

= 474/2 × 970

= 474 × 970/2

= 459780/2 = 229890

Thus, the sum of all terms of the given even numbers from 12 to 958 = 229890

And, the total number of terms = 474

Since, the average of the given numbers

= Sum of the given numbers/Total number of given numbers

Thus, the average of the given even numbers from 12 to 958

= 229890/474 = 485

Thus, the average of the given even numbers from 12 to 958 = 485 Answer


Similar Questions

(1) Find the average of even numbers from 12 to 330

(2) Find the average of even numbers from 12 to 452

(3) What is the average of the first 472 even numbers?

(4) Find the average of even numbers from 8 to 1272

(5) What is the average of the first 1912 even numbers?

(6) What will be the average of the first 4170 odd numbers?

(7) What is the average of the first 1920 even numbers?

(8) Find the average of the first 1851 odd numbers.

(9) Find the average of even numbers from 6 to 884

(10) What is the average of the first 1883 even numbers?


NCERT Solution and CBSE Notes for class twelve, eleventh, tenth, ninth, seventh, sixth, fifth, fourth and General Math for competitive Exams. ©